"Not invented. I had the original concept. It took lots of development, mostly by Barren."

Denison shook his head. "You know, Selene, you're an amazing phenomenon. You should be under observation by the molecular biologists."

"Should I? That's not my idea of a thrill."

"About half a century ago, there came the climax to the big trend toward genetic engineering - "

"I know. It flopped and was thrown out of court. It's illegal now - that whole type of study - insofar as research can be made illegal. I know people who've done work on it just the same."

"I dare say. On Intuitionism?"

"No. I don't think so."

"Ah. But that's my point. At the height of the push for genetic engineering, there was this attempt to stimulate Intuitionism. Almost all the great scientists had intuitive ability, of course, and there was the feeling that this was the single great key to creativity. One could argue that superior capacity for intuition was the product of a particular gene combination and there were all sorts of speculations as to which gene combination that was."

"I suspect that there are many possible types that would satisfy."

"And I suspect that if you are consulting your intuition here, you are correct But there were also those who insisted that one gene, or one small related group of genes, was of particular importance to the combination so that you might speak of an Intuition Gene. . . . Then the whole thing collapsed."

"As I said."

"But before it collapsed," Denison went on, "there had been attempts to alter genes to increase the intensity of Intuitionism and there were those who insisted that some success had been achieved. The altered genes entered the gene pool, I'm positive, and if you happened to inherit -  Were any of your grandparents involved in the program?"

"Not as far as I know," said Selene, "but I can't rule it out. One of them might have been, for all I can say. . . . If you don't mind, I'm not going to investigate the matter. I don't want to know."

"Perhaps not. The whole field grew fearfully unpopular with the general public and anyone who can be considered the product of genetic engineering would not exactly be greeted gladly . . . Intuitionism, they said, for instance, was inseparable from certain undesirable characteristics."

"Well, thank you."

"They said. To possess intuition is to inspire a certain envy and enmity in others. Even as gentle and saint-like an Intuitionist as Michael Faraday aroused the envy and hatred of Humphry Davy. Who's to say that it doesn't take a certain flaw in character t© be capable of arousing envy. And in your case - "

Selene said, "Surely, I don't rouse your envy and hatred?"

"I don't think so. What about Neville, though?"

Selene was silent.

Denison said, "By the time you got to Neville, you were well-known as an Intuitionist, I suppose."

"Not well known, I would say. Some physicists suspected it, I'm sure. However, they don't like to give up credit here any more than on Earth, and I suppose they convinced themselves, more or less, that whatever I had said to them was just a meaningless guess. But Barron knew, of course."

"I see." Denison paused.

Selene's lips twitched. "Somehow I get the feeling that you want to say: 'Oh, that's why he bothers with you.' "

"No, of course not, Selene. You're quite attractive enough to be desired for your own sake."

"I think so, too, but every little bit helps and Barron was bound to be interested in my Intuitionism. Why shouldn't he be? Only he insisted I keep my job as tourist guide. He said I was an important natural resource of the Moon and he didn't want Earth monopolizing me the way they monopolized the synchrotron."

"An odd thought. But perhaps it was that the fewer who knew of your Intuitionism, the fewer would suspect your contribution to what would otherwise be put to his sole credit."

"Now you sound like Barron himself!"

"Do I? And is it possible he gets rather annoyed with you when your Intuitionism is working particularly well."

Selene shrugged. "Barron is a suspicious man. We all have our faults."

"Is it wise to be alone with me, then?"

Selene said, sharply, "Now don't get hurt because I defend him. He doesn't really suspect the possibility of sexual misbehavior between us. You're from Earth. In fact, I might as well tell you he encourages our companionship. He thinks I can learn from you."

"And have you?" asked Denison, coldly.

"I have. . . . Yet though that may be his chief reason for encouraging our friendship, it isn't mine."

"What's yours?"

"As you well know," said Selene, "and as you want to hear me say, I enjoy your company. Otherwise, I could get what I want in considerably less time."

"All right, Selene. Friends?"

"Friends! Absolutely."

"What have you learned from me, then? May I know?"

"That would take awhile to explain. You know that the reason we can't set up a Pump Station anywhere we want to is that we can't locate the para-Universe, even though they can locate us. That might be because they are much more intelligent or much more technologically advanced than we are - "

"Not necessarily me same thing," muttered Denison.

"I know. That's why I put in the 'or.' But it might also be that we are neither particularly stupid nor particularly backward. It might be something as simple as the fact that they offer the harder target. If the strong nuclear interaction is stronger in the para-Universe, they'd be bound to have much smaller Suns and, very likely, much smaller planets. Their individual world would be harder to locate than ours would be.

"Or then again," she went on, "suppose it's the electromagnetic field they detect. The electromagnetic field of a planet is much larger than the planet itself and is much easier to locate. And that would mean that while they can detect the Earth, they can't detect the Moon, which has no electromagnetic field to speak of. That's why, perhaps, we've failed to set up a Pump Station on the Moon. And, if their small planets lack a significant electromagnetic field, we can't locate them."

Denison said, "It's an attractive thought"

"Next, consider the inter-Universal exchange in properties that serves to weaken their strong nuclear interaction, cooling their Suns, while strengthening ours, heating and exploding our Suns. What might that imply? Suppose they can collect energy one-way without our help but only at ruinously low efficiencies. Under ordinary circumstances that would therefore be utterly impractical. They would need us to help direct concentrated energy in their direction by supplying tungsten-186 to them and accepting plutonium-186 in return. But suppose our Galactic arm implodes into a quasar. That would produce an energy concentration in the neighborhood of the Solar system enormously greater than now exists and one that might persist for over a million years.

"Once that quasar forms, even a ruinously low efficiency becomes sufficient. It wouldn't matter to them, therefore, whether we are destroyed or not. In fact, we might argue that it would be safer for them if we did explode. Until we do, we might end the Pump for any of a variety of reasons and they would be helpless to start it again. After the explosion, they are home free; no one could interfere . . . And that's why people who say, 'If the Pump is dangerous, why don't those terribly clever para-men stop it?' don't know what they're talking about"

"Did Neville give you that argument?"

"Yes, he did."

"But the para-Sun would keep cooling down, wouldn't it?"

"What does that matter?" said Selene, impatiently. "With the Pump, they wouldn't be dependent on their Sun for anything."

Denison took a deep breath. "You can't possibly know this, Selene, but there was a rumor on Earth that Lamont received a message from the para-men to the effect that the Pump was dangerous, but that they couldn't stop it. No one took it seriously, of course, but suppose it's true. Suppose Lamont did receive such a message. Might it be that some of the para-men were humanitarian enough to wish not-to destroy a world with cooperating intelligences upon it, and were prevented by the opposition of an oh-so-practicai majority?"

Selene nodded. "I suppose that's possible. . . . All this I knew, or rather, intuited, before you came on the scene. But then you said that nothing between one and the infinite made any sense. Remember?"

"Of course."

"All right. The differences between our Universe and the para-Universe He so obviously in the strong nuclear interaction that so far it's all that's been studied. But there is more than one interaction; there are four. In addition to the strong nuclear, there is the electromagnetic, the weak nuclear, and the gravitational, with intensity ratios of 130:1:10^-10:10^-42. But if four, why not an infinite number,with all the others too weak to be detectable or to influence our Universe in any way,"

Denison said, "If an interaction is too weak to be detectable or to exert influence in any way, then by any operational definition, it doesn't exist."

"In this Universe," said Selene, with a snap. "Who knows what does or does not exist in the para-Universe? With an infinite number of possible interactions, each of which can vary infinitely in intensity compared to any one of them taken as standard, the number of different possible Universes that can exist is infinite."

"Possibly the infinity of the continuum; aleph-one, rather than aleph-null."

Selene frowned. "What does that mean?"

"It's not important. Go on."

Selene said, "Instead, then, of trying to work with the one para-Universe that has impinged itself on us and which may not suit our needs at all, why don't we instead try to work out which Universe, out of all the infinite possibilities, best suits us, and is most easily located. Let us design a Universe, for after all whatever we design must exist, and search for it."

Denison smiled. "Selene, I've thought of exactly the same thing. And while there's no law that states I can't be completely wrong, it's very unlikely that anyone as brilliant as myself can be completely wrong when anyone as brilliant as yourself comes to exactly the same conclusion independently. . . . Do you know what?"

"What?" asked Selene.

"I'm beginning to like your damned Moon food. Or getting used to it, anyway. Let's go back home and eat, and then we can start working out our plans . . . And you know what else?"

"What?"

"As long as we'll be working together, how about one kiss - as experimentalist to intuitionist."

Selene considered. She said, "We've both of us kissed and been kissed a good many times, I suppose. How about doing it as man to woman?"

"I think I can manage that. But what do I do so as not to be clumsy about it? What are the Moon-rules for kissing?"

"Follow instinct," said Selene, casually.

Carefully, Denison placed his arms behind his back and leaned toward Selene. Then, after a while, he placed his arms behind her back.

13

"And then I actually kissed him back," said Selene, thoughtfully.

"Oh, did you?" said Barren Neville, harshly. "Well, that's valor beyond the call of duty."

"I don't know. It wasn't that bad. In fact," (and she smiled) "he was rather touching about it. He was afraid he would be clumsy and began by putting his arms behind his back so that he wouldn't crush me, I suppose."

"Spare me the details."

"Why, what the hell do you care?" she fired up, suddenly. "You're Mister Platonic, aren't you?"

"Do you want it differently? Now?"

"You needn't perform to order."

"But you had better. When do you expect to give us what we need?"

"As soon as I can," she said, tonelessly.

"Without his knowing?"

"He's interested only in energy."

"And in saving the world," mocked Neville. "And in being a hero. And in showing everybody. And in kissing you."

"He admits to all that. What do you admit to?"

"Impatience," said Neville, angrily. "Lots of impatience."

14

"I am glad," said Denison, deliberately, "that the daytime is over." He held out his right arm and stared at it, encased in its protective layers. "The Lunar Sun is one thing I can't get used to and don't want to get used to. Even this suit seems a natural thing to me in comparison."

"What's wrong with the Sun?" asked Selene.

"Don't tell "me you like it, Selene!"

"No, of course not. I hate it. But then I never see it You're an -  You're used to the Sun."

"Not the way it is here on the Moon. It shines out of a black sky here. It dazzles the stars away, instead of muffling them. It is hot, hard, and dangerous. It is an enemy, and while it's in the sky, I can't help but feel that none of our attempts at reducing field intensity will succeed."

"That's superstition, Ben," said Selene, with a distant edge of exasperation. "The Sun has nothing to do with it. We were in the crater shadow anyway and it was just like night. Stars and all."

"Not quite," said Denison. "Anytime we looked northward, Selene, we could see that stretch of Sunlight glittering; I hated to look northward, yet the direction dragged at my eyes. Every time I looked at it I could feel the hard ultraviolet springing at my viewplate."

"That's imagination. In the first place there's no ultraviolet to speak of in reflected light; in the second, your suit protects you against radiation."

"Not against heat. Not very much."

"But it's night now."

"Yes," said Denison with satisfaction, "and this I like." He looked about with a continuing wonder. Earth was in the sky, of course, in its accustomed place; a fat crescent, now, bellying to the southwestward. The constellation Orion was above it, a hunter rising up out of the brilliant curved chair of Earth. The horizon glittered in the dim crescent-Earth light.

"It's beautiful," he said. Then: "Selene, is the Pionizer showing anything?"

Selene, who was looking at the skies' with no comment, stepped toward the maze of equipment that, over the past three alternations of day and night, had been assembled there in the shadow of the crater.

"Not yet," she said, "but that's good news really. The field intensity is holding at just over fifty."

"Not low enough," said Denison.

Selene said, "It can be lowered further. I'm sure that all the parameters are suitable."

"The magnetic field, too?"

"I'm not sure about the magnetic field."

"If we strengthen that, the whole thing becomes unstable."

"It shouldn't. I know it shouldn't."

"Selene, I trust your intuition against everything but the facts. It does get unstable. We've tried it."

"I know, Ben. But not quite with this geometry. It's been holding to fifty-two a phenomenally long time. Surely, if we begin to hold it there for hours instead of minutes, we ought to be able to strengthen the magnetic field tenfold for a period of minutes instead of seconds . . . Let's try."

"Not yet," said Denison.

Selene hesitated, then stepped back, turning away. She said, "You still don't miss Earth, do you, Ben?"

"No. It's rather odd, but I don't. I would have thought it inevitable that I miss blue sky, green earth, flowing water - all the cliche adjective-noun combinations peculiar to Earth. I miss none of them. I don't even dream about them."

Selene said, "This sort of thing does happen sometime. At least, there are Immies who say they experience no homesickness. They're in the minority, of course, and no one has ever been able to decide what this minority has in common. Guesses run all the way from serious emotional deficiency, no capacity to feel anything; to serious emotional excess, a fear to admit homesickness lest it lead to breakdown."

"In my case, I think it's plain enough. Life on Earth was not very enjoyable for two decades and more, while here I work at last in a field I have made my own: And I have your help . . . More than that, Selene, I have your company."

"You are kind," said Selene, gravely, "to place company and help in the relationship you do. You don't seem to need much help. Do you pretend to seek it for the sake of my company?" ' -

Denison laughed softly. Tin not sure which answer would flatter you more."

"Try the truth."

"The truth is not so easy to determine when I value each so much." He turned back to the Pionizer. "The field intensity still holds, Selene."

Selene's faceplate glinted in the Earthlight. She said, "Barren says that non-homesickness is natural and the sign of a healthy mind. He says that though the human body was adapted to Earth's surface and requires adjustment to the Moon, the human brain was not and does not. The human brain is so different, qualitatively, from all other brains that it can be considered a new phenomenon. It has had no time to be really fixed to Earth's surface and can, without adjustment, fit other environments. He says that enclosure in the caverns of the Moon may actually suit it best of all, for that is but a larger version of its enclosure in the cavern of the skull."

"Do you believe that?" asked Denison, amused.

"When Barron talks, he can make things sound very plausible."

"I think it can be made equally plausible to claim that the comfort to be found in the caverns of the Moon is the result of the fulfillment of the return-to-the-womb fantasy. In fact," he added, thoughtfully, "considering the controlled temperature and pressure, the nature and digestibility of the food, I could make a good case for considering the Lunar colony - I beg your pardon, Selene - the Lunar city a deliberate reconstruction of the fetal environment."

Selene said, "I don't think Barren would agree with you for a minute."

"I'm sure he wouldn't," said Denison. He looked at the Earth-crescent, watching the distant cloud banks on edge. He fell into silence, absorbed in the view, and even though Selene moved back to the Pionizer, he remained in place. ' He watched Earth in its nest of stars and looked toward the serrated horizon where, every once in a while, it seemed to him he saw a puff of smoke where a small meteorite might be landing.

He had pointed out a similar phenomenon, with some concern, to Selene during the previous Lunar night. She had been unconcerned.

She said, "The Earth does shift slightly in the sky because of the Moon's libration and every once in a while a shaft of Earth-light tops a small rise and falls on a bit of soil beyond. It comes into view like a tiny puff of rising dust. It's common. We pay no attention."

Denison had said, "But it could be a meteorite sometimes. Don't meteorites ever strike?"

"Of course they do. You're probably hit by several every time you're out Your suit protects you."

"I don't mean micro-dust particles. I mean sizable meteorites that would really kick up the dust. Meteorites that could kill you."

"Well, they fall, too, but they are few and the Moon is large. No one has been hit yet."

And as Denison watched the sky and thought of that, he saw what, in the midst of his momentary preoccupation, he took to be a meteorite. Light streaking through the sky could, however, be a meteorite only on Earth with its atmosphere and not on the airless Moon.

The light in the sky was man-made and Denison had not yet sorted out his impressions when it became, quite clearly, a small rocket-vessel sinking rapidly to a landing beside him.

A single suited figure emerged, while a pilot remained within, barely seen as a dark splotch against the highlights.

Denison waited. The etiquette of the spacesuit required the newcomer joining any group to announce himself first.

"Commissioner Gottstein here," the new voice said, "as you can probably tell from my wobble."

"Ben Denison here," said Denison.

"Yes. I thought as much."

"Have you come here looking for me?"

"Certainly."

"In a space-skipper? You might - "

"I might," said Gottstein, "have used Outlet P-4, which is less than a thousand yards from here. Yes, indeed. But I wasn't looking only for you."

"Well, I won't ask for the meaning of what you say."

"There's no reason for me to be coy. Surely you have not expected me to be uninterested in the fact that you have been carrying on experiments on the Lunar surface."

"It's been no secret and anyone might be interested."

"Yet no one seems to know the details of the experiments. Except, of course, that in some way you are working on matters concerning the Electron Pump."

"It's a reasonable assumption."

"Is it? It seemed to me that experiments of such a nature, to have any value at all, would require a rather enormous setup. This is not of my own knowledge, you understand. I consulted those who would know. And, it is quite obvious, you are not working on such a setup. It occurred to me, therefore, that you might not be the proper focus of my interest. While my attention was drawn to you, others might be undertaking more important tasks."

"Why should I be used as distraction?"

"I don't know. If I knew, I would be less concerned."

"So I have been under observation."

Gottstein chuckled. "That, yes. Since you have arrived. But while you have been working here on the surface, we have observed this entire region for miles in every direction. Oddly enough, it would seem that you, Dr. Denison, and your companion, are the only ones on the Lunar surface for any but the most routine of purposes."

"Why is that odd?"

"Because it means that you really think you're doing something with your gimcrack contraption, whatever it is. I can't believe that you are incompetent, so I think it would be worth listening to you if you tell me what you are doing."

"I am experimenting in para-physics, Commissioner, precisely as rumor has it. To which I can add that so far my experiments have been only partly successful."

"Your companion is, I imagine, Selene Lindstrom L., a tourist guide."

"Yes."

"An unusual choice as an assistant."

"She is intelligent, eager, interested, and extremely attractive."

"And willing to work with an Earthman?"

"And quite willing to work with an Immigrant who will be a Lunar citizen as soon as he qualifies for that status."

Selene was approaching now. Her voice rang in their ears. "Good day, Commissioner. I would have liked not to overhear, and intrude on a private conversation, but, in a spacesuit, overhearing is inevitable anywhere within the horizon."

Gottstein turned. "Hello, Miss Lindstrom. I did not expect to talk in secrecy. Are you interested in para-physics?"

"Oh, yes."